硬脂酸盐对山梨醇类成核剂增透聚丙烯性能的影响

Effect of Stearate on Performance of Transparent Modified Polypropylene with Sorbitol-Based Nucleating Agent

为改善山梨醇类成核剂在使用过程中分散性差、增透效率有限等缺点,将六种硬脂酸盐(锂、钠、钾、钙、锌、铝)作为润滑剂与山梨醇类成核剂复配协同改性聚丙烯(PP)。通过万能试验机、冲击试验机、熔体流动速率仪和雾度仪等设备对试样的光学性能、力学性能和流动性能进行表征。通过扫描电子显微镜(SEM)、偏光显微镜(POM)对改性PP的球晶形态和结晶形貌进行表征。结果表明:与硬脂酸锂、硬脂酸钠和硬脂酸钾相比,硬脂酸钙、硬脂酸锌和硬脂酸铝对PP的增透效果更好。硬脂酸钙、硬脂酸锌和硬脂酸铝在低含量下(≤0.03%),PP的光学性能、力学性能和流动性得到明显改善。硬脂酸钙、硬脂酸锌和硬脂酸铝的加入可以提升山梨醇类成核剂在PP基体中的分散性,从而提高PP的综合性能。

In order to improve the shortcomings of poor dispersion and limited transparent modification efficiency of sorbitol nucleating agents in the use process,six stearates(lithium,sodium,potassium,calcium,zinc,aluminum)were used as lubricants to modify polypropylene(PP)with sorbitol nucleating agents.The optical properties,mechanical properties and flow properties of the samples were characterized by universal testing machine,impact testing machine,melt flow rate meter and haze meter.The spherulite morphology and crystalline morphology of the modified PP were characterized by scanning electron microscopy(SEM)and polarizing microscope(POM).The results show that compared with lithium stearate,sodium stearate and potassium stearate,calcium stearate,zinc stearate and aluminum stearate have better transparent modification effect on PP.The optical properties,mechanical properties and fluidity of PP are significantly improved at low content(≤0.03%)of calcium stearate,zinc stearate and aluminum stearate.The addition of calcium stearate,zinc stearate and aluminum stearate can improve the dispersion of sorbitol nucleating agents in PP matrix,thereby improving the comprehensive properties of PP.